Artificial arm



Dec. 26, 1950 H. T. EDWARDS ARTIFICIAL ARM Filed March 5, 194'? 4 Sheets-Sheet l vweufoz jZZZEdwaws Dec. 26, 1950 H. T. EDWARDS 2,535,489

ARTIFICIAL ARM Filed March 5, 194'. 4 Sheets-Sheet 2 azzwwamzy Dec. 26, 1950 EDWARDS 2,535,489

ARTIFICIAL ARM 4 Sheets-Sheet 5 Filed March 5, 194'? Dec. 26, 1950 EDWARDS 2,535,489

ARTIFICIAL ARM Filed March 5, 1947 4 Sheets-Sheet 4 l i: 2 H ii guucnfoa W, 8. .EZZZ'dZL aFQeS Patented Dec. 26, 1950 m TED STATES v PATENT 0 F F 11c E. 2,535,489 v ARM HaroldT. Edwards, Los Angeles'; Calif. Application March 5, 1947, Serial No. 732,509-

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Cific'aliy to an improved artificial arm structure that includes a shoulder joint, the, wrist joint, and the hand, together with the fingers and thumb of. the hand.

The, primary object of the invention. is the provision of a com aratively light weight arm. structure that' ma'y' be manipulated with facility, and which is composed of jointed-and articulated parts forming eitheranartifi'cial right arm, or a leftarm as herein described and illustrated; and in which the parts are flexibly connected in% order to simulate the movements of natural members. The minimum number of parts. employed in' the structure may with facility be manufactured at comparatively low cost of production, and assembled with convenience to house or contain compactly arranged. eIe'ctro-mechanical power-operated mechanisms for selectively and reversibly'transmi'tti'rig power and motion to th desired parts of thearm'.

, operating means as will hereinafter be described in; detail, and more specifically pointedout in the appended claims. A

In the accompanying drawings I have. illustrated a complete example of aphysicalfembodiment of my invention inwhich-the parts are combined a'nd arranged in accord with-one mode I have devised? for the practical application of the principles of. my invention.- It'WilLhowever,

be understood that various changes and altera-,

tions .are contemplated and may be made inthese exemplifying drawings and mechanical structimes, within. the scope ofv my claims without" departing from the. principles. of' the invention.

Figure 1. is afrontview of an artificial left arm shown as mounted upon anatural shoulder, and

in. Which myv invention. is physically embodied,

andi indicating. also the electrical. control' devices carried at the waistline of the wearer.

Figure 2 is an enlarged'vertical sectionalkview of the.upper armstructure showing. the: shoulder joint together with the. self-contained electromechanical mechanism for activating,- various parts ofth'e-arm.v v

Figure 3 is an. enlarged; front view partly in sectionof thecasingsfor the upper arm and the fore. arm, at theelbow joint;- and Figure 4 is a side view partly in section of the same structure.

' Figure 5- isran enlarged front view partly in section? showing the. handwith fingers. and thumb, together with the wrist joint, and also (or. s--1a)" showing part of the self-contained electromechanical mechanism in the wrist and of the fore arm. H I Y I V Figure 6 is a transverse detail sectional view 5 at line 6-6 of Figure 7- is a; transverse detail sectional view at line 'l'- 'I- of Fig. 2, showing part of the shoulder joint.- 7 p Figure 8 is a cross sectional view at line 8--8" of 10- Fig. 2 looking up into the upper arm.

Figure 9; is a'diagrammatic' view of one of the cable mechanisms-for the fingers.

Inthe general assembly view Fig. 1 where the left arm structure is suspended from a shoulder plate l,- this concave-convex or truncated coneshaped plate of light-weight metal, is fashioned to fit neatly over the shoulder with braces or straps 2-, 2 connected to othersupports carried on the bodyoi the wearer of the artificial arm.

An electric cable 3 composed of various electricwires or circuits extends froma battery 4,:or other source of energy, which may be supported upon a waistline belt:,-.passes upwardly and then under the-shoulder plate; and the various circuit 5. wires are distributedto the different electrical appliancesenclosedin the casings of: the members of the arm.

The upper arm: structure includes a tubular casing 5' of metal-or other light and strong materiah suitable for the purpose; the parts of the forearm are enclosedwithin a tubular casing 6 having. an elbow joint at I, and the palm 8" of the'hand includes a hollow structure flexibly connectedby the-wrist joint 9 to the lower end of 35517118 forearm. The hand is equipped with four tubular fingers Ill, ll', l2, and l-3,-andthe thumb L4,. and these tubular or hollow casings enclose the supporting? frames" upon. which the activating? and operating devices are mounted.

40.: For-suspending the arm structure on thetruncatedshoulder" plate la vertically disposed circular base plate I5 is utilized and the arm. structure is swiveled in a horizontal axis to swing'forward. and backward" simulating the: swing: of a natural arm; For this purpose a horizontally disposed swivel bolt; Hi is threaded in the base plate of the'shoulder'plate orshoulder cap, and aitwo-armyoke- H having a' hub f8 is journaled toswivelon'thebolt. The hub of. the yoke is fashioned with a vertically disposed swivel" pulley 0 arm the cable 20 is guidedby pulleys 22,-22

mountedinbearings on-fthe yoke arms to a} pair of directionchzinging pulleys;23, 23 onshaft mounted. inbearings withinthe upper armcasi-ng 5. The shaft 24 is mounted in a horizontally disposed frame-ring 25 fixed, within-the tubular casing of the upper arm, and from pulleys 23, 23 the swivel cable extends to a pair of power pulleys 26, 26, journaled in bearings within the casing and actuated as will be described.

The arm structure is also capable of swinging in a vertical plane laterally toward and from the body of the wearer, and to accomplish this movement a spindle 21 is journaled in bearings 28 of the frame 25, and the spindle passes through bosses 29 of the yoke arms and is pinned at 30 so that the arm may swing on its bearings 28 of the spindle.

The spindle is equipped with a large operating pulley 3| mounted between the arms of the yoke 11, and an operating cable 32 extends around the pulley 3| with both flights guided by a pair of direction-changing pulleys 33, 33, journaled in bearings fixed within the casing 5, and thence to a pair of power pulleys 34, 34 within the casing.

At the lower end of the tubular casing 5, and just above the elbow joint I, the forearm, together with the elbow joint 35 is suspended and swiveled on a vertical axis that includes an annular ball bearing 36 which is mounted between a bearing ring 3'! fixed within the lower end of the upper arm casing 5, and a stepped opencenter bushing 38 fixed in the upperend of the elbow joint 35, screw rings 39 being provided to retain the bearing members in place. The upper end of this truncated or stepped bushing 38 is fashioned with an exterior annular grooved flange 40 which forms an operating pulley for an operating cable 4| that passes around a direction changing pulley 41a, and from there the cable is wound upon a pair of power pulleys 42, 42 journaled in bearings fixed within the casing 5.

The articulated elbow joint 35, below the swivel joint is hinged or pivotally connected by a cross pin 43 with a rounded head 44 integral with an attaching plate 45 that is fastened by 'screws 46 to a U-shaped frame 41 that closes an opening in the front wall of the forearm casing 6, and the pin 43 passes through bearings in the upper end 48 of the U-shaped frame for suspending the for;arm.

For lifting and lowering the forearm on its pivot-pin 43, an operating pulley 49 is rigidly is connected.

The motor is mounted within the casing 5 of the forearm on a suitable box frame F adjacent the four power pulleys 26, 34, 42, and 53, and

separate cable drives to these power pulleys opopposed trains of gears 63 and B4.

erate them, under electrical control, to transmit.

motion and power to the operating pulleys of Between these laterally spaced oppositely rotating trains of gears are arranged four clutch units for shifting power from one train to the other train, and each clutch unit includes a central shiftable clutch member 65 mounted upon a clutch shaft 66 for alternate co-action with the spaced driven members 67 and 68 of the clutch.

Each clutch is electro-magnetically controlled and operated by means of a solenoid 69 with its core of armature pivotally connected with a clutch lever 13 pivoted at H on the frame F, and the fork 12 of the lever straddles the shiftable clutch member 65, to move the latter against tension of spring 13.

Each clutch shaft 63 is provided with a worm 14 that meshes with a worm gear 15 mounted on a drum shaft 16 journaled in the frame F, and four drive drums 11, I8, 19 and are each provided with a drive cable 8|. One of these cables 8| revolves the pair of reversible power pulleys 26, 26; another drives the power pulleys 34; a third cable operates the power pulleys 42, 42; and the fourth cable 8| drives the power pulleys 53; for operating the four described articulamd parts of the arm. Suitable electrical control devices and circuits are provided for operating the motor and for operating the several electro-magnetically operating parts including the clutch units, for the transmission of power and motion to the respective driving drums, power pulleys, and operating pulleys.

At the wrist joint 9 the hand 8 is firmly secured to the forearm by means of a universal joint mechanism which permits a swiveling twist of the wrist, lateral flexing of the hand, and an up and down fiexion of the hand with relation to the forearm.

The mechanism for operating the wrist joint, and for flexing the articulated knuckle joints of the fingers andthumb, includes another electrical motor and electrical controls, therefor, together with power and motion transmission mechanism including clutches drums and cables and pairs of power pulleys as above described; and this operating mechanism is mounted within the forearm casing 6. I

In Fig. 5 an electric motor is indicated at 82, with some of the electrical controls and power transmission shown at 83 as mounted upon a frame 84 rigidly secured in the tubular casing of the forearm 6. For the swivel twisting movement of the wrist joint on a vertical axis a transversely arranged open-center suspending plate 85 forms part of the supporting frame 34 for a swivel ring 86 that is provided with yoke arms 8! and journaled between the suspending plate 85 and a complementary fixed supporting plate 88. An operating cable 89 passes around a pair of guide pulleys 90, and thence around a central drum 9| mounted upon a horizontal spindle 92 that is journaled in an octagonal swivel ring 93 of the hand 8.

For lateral movements of the hand, the yoke arms 8'! of the swivel ring 85 are pivotally mounted in the octagonal swivel ring by means of radially alined trunnions 94, 94 and pulleys 95, 95, cables 96 and guide pulleys 97 with operating pulleys 98, are turned by the motor operated cables for accomplishing these lateral movements.

For .p and down mo'cement s o the hand of the octagonal swivel ring 93 is pivoted by the spindle 92 in a pair of bearings 99, 99 which form part of the hand frame I99 which is rigidly mounted within the casing 6 of the hand.

The pulley mounts and cable arrangements for moving the joints of the articulated fingers provides for transmission of power and motion, si multaneously, to each joint of the fingers, and the method of pivoting the fingers on frames within the finger casings permits the knuckle joints to spread in a natural manner when the hand is closed.

In Fig. 6 operating cables passing around the three center pulleys 9!, IM and E92 extend to rotary drive drums in the hand operating mechanism, one of which mechanisms includes the cable I03 that transmits power and motion to the little finger. In the diagram Fig. 9 the fingers are each separately controlled from an individually operated motor driven drum as I94 mounted in the forearm, and the operating cable passes around pairs of guide pulleys I95 to the operating pulleys I06 that are journaled in the flexible finger frame I91, and thence around the joint pulleys I96 and I99 within the finger casing I3. A separate and individual pulley, cable and finger frame series identical to that shown in Fig. 9, for each of the four fingers I9, II, I2 and I3 is provided.

In Fig. 5 the construction and operation of the fiexibly jointed thumb is indicated by the use of a frame II9 having two joint pulleys I II and I I2. The operating cable II3 for the thumb is driven from the motor operated drum, and from thence passes around guide pulleys H4 to impart a limited lateral movement to the thumb structure. The cable is looped for operating the joints of the thumb in manner similar to the operating cables of the fingers, the outer joint of the thumb being moved more rapidly than the inner knuckle joints, as at a ratio of one to two, and cable I It operates the thumb on a hing II'I relatively to the palm of the hand 8. The differential ratio of operation of the outer joint or tip section of th thumb relative to the intermediate joints is achieved by making the pulley I I2 of a different size than the pulley I I I, so that said pulley I I2 will rotate twice to each rotation of the pulley III. This ratio can of course be varied as desired.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

In an artificial limb a shoulder support; a first pulley mounted on said support for rotation in a vertical plane; a yoke extended laterally from and rigid with said first pulley; a second pulley rotatably mounted on the yoke in a plane perpendicular to that of the first pulley; an upper arm casing pinned to the second pulley to swing laterally towards and away from said shoulder support on rotation of the second pulley, said casing being supported upon and engaged by the yoke to swing in a plane perpendicular to said plane of lateral swinging movement on oscillation of the yoke responsive to rotation of the first pulley; a drive motor in said upper arm casing; and independent clutch controlled driving connections extending separately from said motor to the first and second pulleys respectively.

2. In an artificial limb a shoulder support; a first pulley mounted on said support for rotation in a vertical plane; a yoke rigid with said first pulley for oscillation on a horizontal axis responsive to rotation of said first pulley; a second pulley mounted on said yoke for rotation in a plane intersecting the plane of rotation of the first pulley at right angles; an upper arm casing pinned to the second pulley so as to be swung laterally towards and away from said shoulder support responsive to rotation of the second pulley, said casing being supported upon and engaged by the yoke to swing forwardly and backwardly relative to said shoulder support responsive to oscillation of the yoke; a forearm casing connected to said upper arm casing for swivelling on a vertical axis; a forearm hinged to said forearm casing; third and fourth pulleys respectively rigid with the forearm casing and forearm respectively; a motor mounted in the upper arm casing; a pair of oppositely rotating gear trains mounted in said upper arm casing and driven by the motor; and a plurality of driving connections extended from said gear train to said first, second, third and fourth pulley respectively, said driving con nections being independently clutch controlled for independent shifting of said driving connections to either gear train.

3. In an artificial limb a shoulder support; a first pulley mounted for rotation upon said shoulder support; a hinge yoke rigid with said first pulley; a second pulley mounted for rotation upon said hinge yoke; an upper arm casing pinned to the second pulley for swinging in one direction responsive to rotation of the second pulley, said upper arm casing being engaged by the yoke for swinging in another direction responsive to yoke oscillation on rotation of the first pulley; a forearm casing swivelly connected to the upper arm casing; a third pulley rigid with said forearm casing; a forearm hinged to the forearm casing; a fourth pulley pinned to the forearm and rotatably mounted in the forearm casing; a driving motor mounted in the upper arm casing; a pair of oppositely rotating trains of gears mounted in said upper arm casing a driving connection between said motor and said trains of gears for continuously rotating the gears of the train, said gear trains including a plurality of opposed pairs of oppositely rotating gears; a driving connection extending from each of said pairs to a different one of said first, second, third and fourth pulleys, said driving connections bein independent of each other; and a separate double clutch mounted between the gears of each pair of gears and shiftable to either gear of a pair for engaging the driving connection extending to each pulley with a selected ear.

HAROLD T. EDWARDS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,366,453 Henning c Jan. 25, 1921 1,458,923 Anderson June 19, 1923 1,507,683 Pecorella et a1 Sept. 9, 1924 FOREIGN PATENTS Number Country Date 153,591 Austria June 10, 1938 168,473 Great Britain Sept. 8, 1921 248,698 Italy June 2, 1926 297,320 Germany Apr. 11, 1917 OTHER REFERENCES Berger, Meyer, Arm Powered by Electric Motor Revealed as Boon to War Amputees, the New York Times, July 19, 1946 (clipping). 

